1. Field
The present application relates generally to the operation and design of analog front ends, and more particularly, to the operation and design of guard rings to improve circuit isolation.
2. Background
Wireless devices are becoming increasing more complicated and now routinely provide multi-mode and multi-band operation. As a result, efficient utilization of circuit area has become a primary concern. To address this concern, smaller radio frequency integrated circuits (RFICs) are being developed. However, as RFICs become smaller in size with increasing functionality, maintaining isolation between the various circuits on the RFICs has become more and more challenging. For example, a single RFIC may include multiple circuits that operate in multiple frequency bands, respectively. Thus, an inductor of one circuit operating at a selected frequency may radiate an associated magnetic field that couples to inductors utilized in other circuits of the RFIC. This cross coupling of magnetic fields can result in degraded performance of one or more of the circuits on an RFIC. One technique used to overcome this cross coupling is to provide greater separation between the various circuits on the RFIC. Unfortunately, this may result in less efficient utilization of circuit area and larger RFICs that may not be suitable for small wireless devices.
Therefore, it would be desirable to have a mechanism for improved circuit isolation for use with RFICs to facilitate efficient utilization of circuit area.